Preparation Of Grafted Starch Resin And Its Performance On Dye Wastewater Treatment

Three different dye adsorption materials were prepared by different methods using starch in this paper: a non-degradable GSR for replacing 001×7 ion exchange resin and two fully degradable grafted starches CS-?CD and CS-?CD.The optimal conditions for the synthesis of three kinds of adsorbent materials were optimized,and their physical and chemical properties,adsorption properties to dyes and their degradation properties were studied.GSR is a grafted starch resin with a strong acid ion exchange group(sulfonic acid group)prepared by graft copolymerization of styrene and sodium methacrylate.GSR resin has good adsorption and regeneration performance.In dynamic adsorption,the first decolorization rate of high-concentration mixed wastewater composed of methylene blue,saffron T,malachite green and rhodamine B is as high as 99.85%.After three regeneration cycles,the decolorization rate is still 92.36%,which is not lower than 92.51% of the first adsorption.The structural characterization and acid-base resistance test results show that the GSR structure is difficult to degrade,which makes it show good in dynamic(column bed)continuous operation adaptability.CS-?CD grafted ?-cyclodextrin onto starch macromolecules with citric acid as crosslinker to prepare a novel,fully degradable ?-cyclodextrin grafted starch.The decolorization rate of CS-?CD for mixed wastewater composed of methylene blue,methyl violet and basic fuchsine is as high as 90%,higher than that of natural starch,diatomite and zeolite.Moreover,the enzymatic hydrolysis rate of CS-?CD is much lower than that of CS and ?-CD can resist microbial decomposition for a long time,maintain molecular structure stability and improve application performance.It is an environmentally effective dye wastewater treatment agent.CS-?CD is a high-adsorption material ?-cyclodextrin grafted starch with good degradation performance by grafting ?-cyclodextrin onto the starch macromolecule with epichlorohydrin as cross-linking agent.?-CD has a larger cavity than ?-CD,which is more enveloped for different dyes and increases the broad spectrum of adsorption.CS-?CD has a decolorization rate of 87.15% for high-concentration mixed dye wastewater composed of methylene blue,methyl violet and Congo red.The adsorption performance of different dyes is significantly improved compared with other adsorbents,especially for anionic dyes with larger molecular size.The increase of Congo red is the most obvious.The GPC results show that the molecular weight of CS-?CD is increased and the structure is more complex.The degradation rate of CS-?CD is much lower than that of CS and ?-CD.It is an environmentally effective and effective wastewater treatment agent.